Abstract: Ocean wind field is one of the important ocean and atmospheric parameters. Fully polarimetric microwave radiometer is a new type of microwave remote sensors. Multi-channel digital correlation technology is used in digital fully polarimetric microwave radiometer, with the horizontal and vertical polarization signal correlated to obtain brightness temperature Stokes vector for the inversion transformation of sea surface wind field model. This paper describes system design methods of polarimetric microwave radiometer, including RF front-end, the IF part and digital correlator. At the same time, the system internal and external calibration method are given, and detailed theoretical analysis and hardware design are introduced.